1. Field of the Invention
The present invention relates to a technique for providing map information stored in a database via a network, for example, the internet. More specifically, the present invention relates to a system for and a method of calculating an optimum route between two points designated by a user and displaying the calculated route on a user terminal.
2. Description of the Prior Art
Nowadays, on the internet using the internet protocol, various information from around the world are provided and exhibited by WWW (World Wide Web) servers, and a user can obtain desired and/or necessary information by operating a user terminal connected to the internet to make the information search or retrieval. There are a number of various information services offered via the internet, and a map information search and display service is one of them. In this kind of service, a user can search and download desired map information and display it on his or her user terminal by accessing the WWW server having a map database via the internet. Specifically, when a user designates an address, a place name, a station or a name of a certain facility or shop, the map around that designated place appears on the user terminal as a picture. Therefore, the user can readily recognize the exact position of the place of interest, such as the station, facility, etc., by referring to the map picture displayed on the user terminal.
One prime purpose that the user uses the map information search and display service is to know the route to a certain destination. In such a case, the user searches and displays the map around the destination by using this service, and judges and determines, by himself, the best route in consideration of the geographical information such as roads, trains, etc.
It is an object of the present invention to provide map information providing system and method capable of promptly calculating and displaying the best route (i.e., guidance information advising the best road to choose and/or necessary turns at the corners, etc.) to a certain destination together with the map information around there.
According to one aspect of the present invention, there is provided a map information providing system including: a main server for communicating with a user terminal via a network; a route calculation server for receiving starting point data and destination data corresponding to a starting point and a destination which a user designates by the user terminal, and for calculating a route from the starting point to the destination; a map server including a map database and for communicating with the user terminal via the network, wherein the route calculation server stores calculated route data together with route identification information associated with the route data, and transmits the route identification information to the user terminal via the network, and wherein the map server receives the route identification information from the user terminal via the network, obtains the route data associated with the route identification information from the route calculation server, produces route display picture data including map picture on which the calculated route is represented, and transmits the route display picture data to the user terminal.
In accordance with the system thus configured, the route calculation server receives starting point data and destination data corresponding to a starting point and a destination which a user designates by the user terminal, and calculates a route from the starting point to the destination. The map server includes a map database, and communicates with the user terminal via the network. The route calculation server stores calculated route data together with route identification information associated with the route data, and transmits the route identification information to the user terminal via the network. The map server receives the route identification information from the user terminal via the network, obtains the route data associated with the route identification information from the route calculation server, produces route display picture data including map picture on which the calculated route is represented, and transmits the route display picture data to the user terminal.
In this way, when the user designates desired starting point and the destination on the user terminal, the route calculation is performed based on the designated starting point and the destination. Therefore, the user can easily and promptly view the route display picture including the calculated route on the user terminal. Further, since the calculated route data is not transmitted to the terminal device, but the route identification information associated with the calculated route data is transmitted to the user terminal, there is no need to transmit large amount of data via the network between the user terminal and the servers, thus accelerating the processing and reducing the burden on the data transmission.
In a preferred embodiment, the route calculation server may receive calculation condition information, which the user designates by the user terminal, via the network, and calculate the route which satisfies the calculation condition information. By this, the user can precisely designate the calculation condition according to his or her needs and obtain the route satisfying the conditions.
Preferably, the route display picture data may include map picture data of a single map picture on which the starting point, the destination and the calculated route are represented. By this, the user can grasp the route at a glance. Further, the route points on the calculated route may be additionally represented on the single map picture. Thus, the user can easily know the important route points on the way to the destination.
According to another aspect of the present invention, there is provided a map information providing method performed in a system which provides route information to a user of a user terminal via a network and which includes a map server including a map database and connected to the network, and a main server connected to the network, the method including the steps of: receiving starting point data and destination data corresponding to a starting point and a destination which a user designates by the user terminal, and calculating a route from the starting point to the destination; storing route data of the calculated route together with route identification information associated with the route data; transmitting the route identification information to the user terminal via the network; at the map server, receiving the route identification information from the user terminal; at the map server, obtaining the route data associated with the route identification information, producing route display picture data including map picture on which the calculated route is represented by referring to the map database, and transmitting the route display picture data to the user terminal.
Preferably, the step of calculating the route may include the steps of: receiving calculation condition information that the user designates by the user terminal; and calculating the route which satisfies the calculation condition information.
According to still another aspect of the present invention, there is provided a map information providing method performed in a system which provides route information to a user of a user terminal via a network and which includes a map server including a map database, a main server and a route calculation server which are connected to the network, the method including the steps of: at the main server, receiving starting point data and destination data corresponding to a starting point and a destination, which a user designates by the user terminal, via the network; transmitting the starting point data and the destination data from the main server to the route calculation server via the network; at the route calculation server, calculating a route from the starting point to the destination and storing route data of the calculated route together with route identification information associated with the route data; transmitting the route data and the route identification data from the route calculation server to the main server; transmitting the route identification information from the main server to the user terminal via the network; at the map server, receiving the route identification information from the user terminal; at the map server, transmitting the route identification information to the route calculation server and receiving the route data associated with the route identification information from the route calculation server; and at the map server, producing route display picture data including map picture, on which the calculated route is represented, based on the route data and the map database, transmitting the route display picture data to the user terminal, and controlling the user terminal to display the route display picture data.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiment of the invention when read in conjunction with the accompanying drawings briefly described below.